Baylor studies Alzheimer's vaccine

An experimental vaccine for people with mild to moderate Alzheimer's disease is undergoing phase II clinical trials at Baylor College of Medicine.

The study investigates the safety and effectiveness of vaccinating patients with a protein similar to one produced in the brains of Alzheimer's patients. Baylor is one of 20 institutions across the country participating in the study.

"The idea behind the Alzheimer's vaccine is exciting because no therapies currently can prevent Alzheimer's or stop the progression of the disease," said Dr. Rachelle Doody, principal investigator of the study and director of the Alzheimer's Disease Center at Baylor. "We look forward to discovering the vaccine's true potential."

Participants will be inoculated with amyloid protein in a vaccine formulation with the goal of activating the body's immune system to produce antibodies. Elan Pharmaceuticals, Inc. commercially produces the vaccine.

In earlier animal studies, the vaccine caused an immune response that cleared out beta amyloid plaques in the brains of mice. The build up of amyloid plaques is also a hallmark of Alzheimer's disease in humans.

During the 16-month study, study participants will be randomly assigned to either receive several doses of the vaccine or a placebo. They will regularly undergo testing to gauge their cognitive skills and MRIs to determine the vaccine's effect on the brain.

"While an MRI cannot show any change in plaque levels in the brain, it can show whether the brain is continuing to shrink or not, which is a sign of advancing Alzheimer's," Doody said.

A total of 375 people worldwide will participate in the study, with more than 20 at Baylor. However, sites are no longer accepting patients into the trial, since it is full.

"There has been massive public interest in this study based on results of the vaccine in mice," Doody said. "But it is important for the public to know that while this vaccine could be a promising treatment for Alzheimer's, it is just in the beginning stages of research and is not a cure."

Four million Americans have Alzheimer's disease. That number will jump to 14 million by the year 2050, according to the Alzheimer's Association. The degenerative brain disease usually begins gradually, causing a person to forget recent events or familiar tasks. The brain disease eventually causes confusion, personality and behavior changes and impaired judgment. Communication becomes difficult as the affected person struggles to find words, finish thoughts or follow directions. Eventually, most people with untreated Alzheimer's disease become unable to care for themselves.